A current mirror circuit generates a constant output electrical current from a reference electrical current in an integrated circuit (IC). The term “mirror” refers to the act of copying the reference electrical current to generate the output electrical current. Current mirror circuits are mostly utilized to supply current to other circuits or, in some instances, to form an active load for circuits.
There are many different types of current mirror circuits, for example, baseline current mirror circuits, cascode current mirror circuits, and Wilson current mirror circuits. Each type of current mirror circuits may have different circuit characteristics. Several circuit characteristics that are usually used for defining a particular current mirror circuit may be output impedance, current gain factor, and output voltage swing.
A current mirror circuit with an output electrical current that is not proportional to its reference electrical current may be a defective current mirror circuit. Generally, a defective current mirror circuit may be caused by large variations in the integrated circuit manufacturing process. A defective current mirror circuit may be repaired by changing the layout masks where the defects are observed. However, changing layout masks to resolve this issue may be costly and thus unfavorable.
It is within this context that the embodiments described herein arise.